f2fs: fix readdir incorrectness

In the previous Al Viro's readdir patch set, there occurs a bug when
running
xfstest: 006 as follows.

[Error output]
alpha size = 4, name length = 6, total files = 4096, nproc=1
1023 files created
rm: cannot remove `/mnt/f2fs/permname.15150/a': Directory not empty

[Correct output]
alpha size = 4, name length = 6, total files = 4096, nproc=1
4097 files created

This bug is due to the misupdate of directory position in ctx.
So, this patch fixes this.

[AV: fixed a braino]

CC: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 9d1cd423450d1ba12049a987a0e5478424a33850..62f0d5977c64f3526e0720653fe33039c85355e3 100644 (file)
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -610,13 +610,12 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)
 {
        struct inode *inode = file_inode(file);
        unsigned long npages = dir_blocks(inode);
-       unsigned int bit_pos = 0, start_bit_pos = 0;
+       unsigned int bit_pos = 0;
        struct f2fs_dentry_block *dentry_blk = NULL;
        struct f2fs_dir_entry *de = NULL;
        struct page *dentry_page = NULL;
        unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
        unsigned char d_type = DT_UNKNOWN;
-       int slots;
 
        bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK);
 
@@ -625,7 +624,6 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)
                if (IS_ERR(dentry_page))
                        continue;
 
-               start_bit_pos = bit_pos;
                dentry_blk = kmap(dentry_page);
                while (bit_pos < NR_DENTRY_IN_BLOCK) {
                        bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
@@ -634,19 +632,19 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)
                        if (bit_pos >= NR_DENTRY_IN_BLOCK)
                                break;
 
-                       ctx->pos += bit_pos - start_bit_pos;
                        de = &dentry_blk->dentry[bit_pos];
                        if (de->file_type < F2FS_FT_MAX)
                                d_type = f2fs_filetype_table[de->file_type];
                        else
                                d_type = DT_UNKNOWN;
                        if (!dir_emit(ctx,
-                                     dentry_blk->filename[bit_pos],
-                                     le16_to_cpu(de->name_len),
-                                     le32_to_cpu(de->ino), d_type))
-                               goto success;
-                       slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
-                       bit_pos += slots;
+                                       dentry_blk->filename[bit_pos],
+                                       le16_to_cpu(de->name_len),
+                                       le32_to_cpu(de->ino), d_type))
+                               goto stop;
+
+                       bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
+                       ctx->pos = n * NR_DENTRY_IN_BLOCK + bit_pos;
                }
                bit_pos = 0;
                ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
@@ -654,7 +652,7 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)
                f2fs_put_page(dentry_page, 1);
                dentry_page = NULL;
        }
-success:
+stop:
        if (dentry_page && !IS_ERR(dentry_page)) {
                kunmap(dentry_page);
                f2fs_put_page(dentry_page, 1);